(1) You can't change a password, per se. Go to TOOLS > OPTIONS >SECURITY > PASSWORDS tab> SAVED PASSWORDS button and there you can delete old passwords. Restart Thunderbird to ensure that the stored password is cleared from memory. The next time you "Get Mail" Thunderbird will ask for the password and you can check the box to remember the value.

(2) Are you composing in plain text or HTML? That's controlled under Tools->Account Setting->Composition & Addressing.

DanRaisch wrote:(1) You can't change a password, per se. Go to TOOLS > OPTIONS >SECURITY > PASSWORDS tab> SAVED PASSWORDS button and there you can delete old passwords. Restart Thunderbird to ensure that the stored password is cleared from memory. The next time you "Get Mail" Thunderbird will ask for the password and you can check the box to remember the value.

I did find that eventually and it works, but again it was well hidden !

(2) Are you composing in plain text or HTML? That's controlled under Tools->Account Setting->Composition & Addressing.

Plaintext - as all Emails should be.

I did eventually find a way of doing this hidden away in Tools>Options>Display>Plaintext messages>Style>Size>Colour. Good grief !